Multi-orientation canister for use with a reduced pressure treatment system

ABSTRACT

Systems and methods for reduced pressure tissue treatments, including a multi-orientation canister. The canister includes an inlet for receiving fluids from a tissue site, and a main chamber in fluid communication with the inlet for receiving fluids from the inlet. The canister includes a filter chamber separated from the main chamber by one or more filter chamber walls. The one or more filter chamber walls includes a primary hole having a first diameter and a secondary hole having a second diameter smaller than the first diameter. The primary hole provides a first path of fluid communication between the filter chamber and the main chamber. The canister includes an outlet for providing fluid communication between the filter chamber and a reduced pressure source.

FIELD OF THE INVENTION

The present invention relates generally to reduced pressure treatmentsystems and more particularly to a multi-orientation canister for usewith a reduced pressure treatment system.

DESCRIPTION OF RELATED ART

Clinical studies and practice have shown that providing a reducedpressure in proximity to a tissue site augments and accelerates thegrowth of new tissue at the tissue site. The applications of thisphenomenon are numerous, but one particular application of reducedpressure involves treating wounds. This treatment (frequently referredto in the medical community as “negative pressure wound therapy,”“reduced pressure therapy,” or “vacuum therapy”) provides a number ofbenefits, including migration of epithelial and subcutaneous tissues,improved blood flow, and micro-deformation of tissue at the wound site.Together these benefits result in increased development of granulationtissue and faster healing times. Typically, reduced pressure is appliedby a reduced pressure source to tissue through a porous pad or othermanifold device. The porous pad contains cells or pores that are capableof distributing reduced pressure to the tissue and channeling fluidsthat are drawn from the tissue. The porous pad often is incorporatedinto a dressing having other components that facilitate treatment.Fluids drawn from the tissue site are often collected in a canister.

SUMMARY

The problems presented by existing reduced pressure treatment systemsare solved by the systems and methods of the illustrative embodimentsdescribed herein. In one illustrative embodiment, a multi-orientationcanister for use in a reduced pressure tissue treatment includes aninlet adapted to be fluidly connected with a tissue site, the inletbeing capable of receiving fluids from the tissue site, and a mainchamber in fluid communication with the inlet for receiving fluids fromthe inlet. The multi-orientation canister further includes a filterchamber separated from the main chamber by one or more filter chamberwalls. The one or more filter chamber walls includes a primary holehaving a first diameter and a secondary hole having a second diametersmaller than the first diameter. The primary hole is positioned throughthe one or more filter chamber walls for providing a first path of fluidcommunication between the filter chamber and the main chamber. Themulti-orientation canister further includes an outlet for providingfluid communication with the filter chamber such that the outlet isadapted to be fluidly connected to a reduced pressure source.

In another illustrative embodiment, a canister for use in a reducedpressure tissue treatment includes one or more canister walls arrangedto create an enclosure with a main chamber and a filter chamberpositioned within the enclosure. The main chamber may collect exudatereceived by a tissue site. The filter chamber has a first filter chamberwall and a second filter chamber wall for partitioning the filterchamber from the main chamber. A first aperture extends through thefirst filter chamber wall spaced apart from the one or more canisterwalls. A second aperture smaller than the first aperture extends throughthe second filter chamber wall.

In yet another illustrative embodiment, a canister for use in a reducedpressure tissue treatment includes a main chamber having an inletadapted to receive liquid from a tissue site and a filter chamberisolated from the main chamber by one or more walls. The filter chamberhas an outlet adapted to be fluidly coupled to a reduced pressuresource. A first aperture and a second aperture extend through the one ormore walls. The first aperture is configured to provide fluidcommunication between the main chamber and the filter chamber until thefirst aperture is occluded by the liquid. Upon occlusion of the firstaperture by the liquid, the second aperture is configured to providefluid communication between the main chamber and the filter chamber.

In another illustrative embodiment, a liquid-collection canisterincludes a first and second chamber fluidly isolated by one or morewalls and a plurality of apertures positioned in the one or more wallsto provide fluid communication between the first and second chambers.The plurality of apertures are not covered by a membrane.

In another illustrative embodiment, a canister for use in a reducedpressure tissue treatment includes a main chamber having an inletadapted to receive liquid from a tissue site and a filter chamberisolated from the main chamber by one or more walls. The filter chamberincludes an outlet adapted to be fluidly coupled to a reduced pressuresource. The canister further includes a filter positioned within thefilter chamber as well as a first aperture and a second apertureextending through the one or more walls. The first and second aperturesare sized to prevent fluid, upon entrance into the main chamber, fromincidentally contacting the filter.

In yet another illustrative embodiment, a reduced pressure deliverysystem for applying a reduced pressure tissue treatment to a tissue siteincludes a multi-orientation canister. The multi-orientation canisterincludes one or more canister walls arranged to create an enclosure, amain chamber positioned within the enclosure for receiving exudate froma tissue site, and a filter chamber positioned within the enclosure. Thefilter chamber has a first filter chamber wall and a second filterchamber wall for partitioning the filter chamber from the main chamber.A first aperture extends through the first filter chamber wall spacedapart from the one or more canister walls, and a second aperture smallerthan the first aperture extends through the second filter chamber wall.The system further includes a reduced pressure source fluidly connectedto the multi-orientation canister for applying reduced pressure to thetissue site, a manifold positioned adjacent the tissue site, and aconduit fluidly connected between the main chamber and the manifold fordelivering fluids from the tissue site to the main chamber.

In another illustrative embodiment, a reduced pressure delivery systemfor applying a reduced pressure tissue treatment to a tissue siteincludes a liquid-collection canister. The liquid-collection canisterincludes a first and second chamber fluidly isolated by one or, morewalls, and a plurality of apertures positioned in the one or more wallsto provide fluid communication between the first and second chambers.The plurality of apertures are not covered by a membrane. The systemfurther includes a reduced pressure source for applying reduced pressureto the tissue site, a manifold positioned adjacent the tissue site, anda conduit fluidly connected between the main chamber and the manifoldfor delivering fluids from the tissue site to the main chamber.

In another illustrative embodiment, a method for emptying fluids from afilter chamber positioned in a canister used in reduced pressure tissuetreatment includes the steps of receiving fluids into a main chamber ofthe canister and rotating the canister into a first position to causefluids in the main chamber to flow into the filter chamber througheither a first aperture or a second aperture. The first aperture islarger than the second aperture, and the first aperture is located in afirst plane substantially perpendicular to a second plane of which thesecond aperture is located. The method further includes the step ofrotating the canister into a second position to cause fluids in thefilter chamber to flow back into the main chamber through the firstaperture.

In yet another illustrative embodiment, a method for extending the useof a filter positioned in a multi-orientation canister used in reducedpressure tissue treatment includes the step of receiving fluids into amain chamber of the multi-orientation canister such that the fluidsreact with a gelling agent to create a gel. The method further includesapplying reduced pressure to the main chamber via a first aperturepositioned in a partition that separates the main chamber from a filterchamber until a fluid or gel level in the main chamber covers the firstaperture thereby causing a temporary blockage of the first aperture. Themethod further includes the step of responsive to the first aperturebecoming temporarily blocked, continuing to apply reduced pressure tothe main chamber via a second aperture positioned in the partition untilthe fluid or gel level in the main chamber covers the second aperture.The first aperture is a distance, D, from the second aperture. Themethod further includes the step of responsive to the fluid or gel levelcovering the second aperture, continuing to apply reduced pressure tothe main chamber through the first aperture causing the gel in the mainchamber to pulled into the filter chamber until both the main chamberand the filter chamber are substantially full of gel.

Other objects, features, and advantages of the illustrative embodimentswill become apparent with reference to the drawings and detaileddescription that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view, with a portion shown incross-section, of a reduced pressure treatment system, including amulti-orientation canister;

FIG. 2 illustrates a perspective view of one illustrative embodiment ofa multi-orientation canister, with a portion shown with hidden lines,for use with the reduced pressure treatment system illustrated in FIG.1;

FIG. 3 illustrates a perspective, exploded view of the multi-orientationcanister illustrated in FIG. 2;

FIG. 4 illustrates another perspective, exploded view of themulti-orientation canister illustrated in FIG. 2;

FIG. 5 illustrates a perspective view of the multi-orientation canisterof FIG. 2 with a back face plate and the attached clip removed;

FIG. 6 illustrates a sectional view of the multi-orientation canister ofFIG. 5 taken along line 6-6; and

FIG. 7 illustrates a sectional view of the multi-orientation canister ofFIG. 5 taken along line 7-7.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description of several illustrativeembodiments, reference is made to the accompanying drawings that form apart hereof, and in which is shown by way of illustration specificpreferred embodiments in which the invention may be practiced. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the invention, and it is understood that otherembodiments may be utilized and that logical structural, mechanical,electrical, and chemical changes may be made without departing from thespirit or scope of the invention. To avoid detail not necessary toenable those skilled in the art to practice the embodiments describedherein, the description may omit certain information known to thoseskilled in the art. The following detailed description is, therefore,not to be taken in a limiting sense, and the scope of the illustrativeembodiments are defined only by the appended claims. Unless otherwiseindicated, as used herein, “or” does not require mutual exclusivity.

The term “reduced pressure” as used herein generally refers to apressure less than the ambient pressure at a tissue site that is beingsubjected to treatment. In most cases, this reduced pressure will beless than the atmospheric pressure at which the patient is located.Alternatively, the reduced pressure may be less than a hydrostaticpressure associated with tissue at the tissue site. Although the terms“vacuum” and “negative pressure” may be used to describe the pressureapplied to the tissue site, the actual pressure reduction applied to thetissue site may be significantly less than the pressure reductionnormally associated with a complete vacuum. Reduced pressure mayinitially generate fluid flow in the area of the tissue site. As thehydrostatic pressure around the tissue site approaches the desiredreduced pressure, the flow may subside, and the reduced pressure is thenmaintained. Unless otherwise indicated, values of pressure stated hereinare gauge pressures. Similarly, references to increases in reducedpressure typically refer to a decrease in absolute pressure, whiledecreases in reduced pressure typically refer to an increase in absolutepressure.

Reduced pressure treatment systems often use canisters for collectingexudate, including liquids and other fluids, received from a tissue siteundergoing reduced pressure tissue treatment. Exudate collected withinthe canister may move within the canister by way of splashing orsloshing for a number of reasons. For example, when the exudate entersthe canister, they may splash or foam within the canister enclosure.Likewise, once the exudate has entered the canister, the exudate mayslosh due to canister movement. In some circumstances, the canister isworn by a patient and may be subject to orientation changes as thepatient bends over or moves in general. The movement of the exudatewithin the canister may cause the exudate to come into contact with afilter used to protect the reduced pressure source from contamination.

The filter may be positioned within the canister to block unwantedliquids from contaminating the reduced pressure source. When woundexudate contacts the filter, even if the contact is brief, such as whenthe filter is splashed by exudate or the canister undergoes a brieforientation change due to patient movement, the exudate may leave aprotein film or deposit on the filter. The protein deposits can build-upon the filter as the filter is subject to repeated and prolonged contactwith exudate, compromising the filter's ability to allow air flowbetween the canister and the reduced pressure source.

A blocked or compromised filter can create at least two problems. Thefirst problem is that restricting air flow between the canister and thereduced pressure source causes air flow restriction at the wound site.Restricting the ability of the reduced pressure system from drawing airfrom the tissue site results in an inability to maintain reducedpressure at the tissue site. The other problem is that when the air flowbetween the canister and the reduced pressure source is restricted, analarm may sound indicating that the canister is full and needs to beemptied or changed, when, in fact, the canister is not full. Reducedpressure therapy systems may have an alarm indicating that a canister isfull based on reduced pressure no longer being supplied to the tissuesite at a desired treatment level. Since false canister-full alarms areboth wasteful in time and resources, it would be beneficial for acanister that is configured to be worn on a patient's body, and istherefore, subject to orientation changes, to have a means forprotecting the filter from contacting exudate until the canister istruly full of exudate. Additionally, it would be beneficial for thecanister to be able to drain unwanted exudate away from the filter inthe event the exudate contacts the filter before the canister is full.

Referring to FIG. 1, an illustrative embodiment of a reduced pressuretreatment system 100 for treating a tissue site 102 on a patientincludes a dressing 104 placed proximate the tissue site 102, and areduced pressure treatment unit 106 fluidly coupled to the dressing 104via a reduced pressure connector 108 and a conduit 110. As used herein,the term “tissue site” may refer to a wound or defect located on orwithin any tissue, including but not limited to, bone tissue, adiposetissue, muscle tissue, neural tissue, dermal tissue, vascular tissue,connective tissue, cartilage, tendons, or ligaments. The term “tissuesite” may further refer to areas of any tissue that are not necessarilywounded or defective, but are instead areas in which it is desired toadd or promote the growth of additional tissue. For example, reducedpressure tissue treatment may be used in certain tissue areas to growadditional tissue that may be harvested and transplanted to anothertissue location.

The dressing 104 may include a manifold 112 placed proximate the tissuesite 102, a reduced pressure interface 114 fluidly coupled to themanifold 112, and a drape 116. The drape 116 may be placed over themanifold 112 to secure the manifold 112 at the tissue site 102 and tocreate a fluidly sealed space 113 that is located beneath the drape andthat is at least partially occupied by the manifold 112. In oneembodiment, the drape 116 extends beyond a perimeter of the tissue site102 and is placed over a patient's epidermis 118 to create the fluidlysealed space 113 between the drape 116 and the epidermis 118. The drape116 may include an adhesive 120 or bonding agent to secure the drape 116to the epidermis 118. In one embodiment, the adhesive 120 may be used tocreate a seal between the drape 116 and the epidermis 118 to preventleakage of reduced pressure from the tissue site 102. In anotherembodiment, a seal layer (not shown) such as, for example, a hydrogel orother material may be disposed between the drape 116 and the epidermis118 to augment or substitute for the sealing properties of the adhesive120. As used herein, “fluid seal” means a seal adequate to maintainreduced pressure at a desired site given the particular reduced pressuresource involved.

The term manifold generally refers to a substance or structure that isprovided to assist in applying reduced pressure to, delivering fluidsto, or removing fluids from, the tissue site 102. The manifold 112typically includes a plurality of flow channels or pathways thatdistribute fluids provided to and removed from the tissue site aroundthe manifold 112. In one illustrative embodiment, the flow channels orpathways are interconnected to improve distribution of fluids providedor removed from the tissue site 102. Examples of manifolds 112 mayinclude, for example, without limitation, devices that have structuralelements arranged to form flow channels, such as, for example, cellularfoam, open-cell foam, porous tissue collections, liquids, gels, andfoams that include, or cure to include, flow channels. In oneembodiment, the manifold 112 is a porous foam and includes a pluralityof interconnected cells or pores that act as flow channels. The porousfoam may be a polyurethane, open-cell, reticulated foam such asGranuFoam® material manufactured by Kinetic Concepts, Incorporated ofSan Antonio, Tex. Other embodiments may include “closed cells.”

Referring still to FIG. 1, the reduced pressure interface 114 may bepositioned adjacent to or coupled to the drape 116 to provide fluidaccess to the manifold 112. The reduced pressure interface 114 may becoupled to the drape 116 by an adhesive 121 similar to the adhesive 120described above. The conduit 110 and the reduced pressure connector 108fluidly couple the reduced pressure treatment unit 106 and the reducedpressure interface 114. The reduced pressure interface 114 allows thereduced pressure to be delivered to the tissue site 102. While theamount and nature of reduced pressure applied to the tissue site 102will typically vary according to the application, the reduced pressuretreatment unit 106 will typically provide reduced pressure between −5 mmHg and −500 mm Hg and more typically between −100 mm Hg and −300 mm Hg.

The reduced pressure treatment unit 106 may include a canister 122 forcollecting exudate and a sensing unit 130 in fluid communication with areduced pressure source 124. While FIG. 1 illustrates that the reducedpressure treatment unit 106 houses the canister 122, the sensing unit130, and the reduced pressure source 124 in a single housing unit, itshould be appreciated that elements of the reduced pressure treatmentunit 106, which may include the canister 122, the sensing unit 130, andthe reduced pressure source 124, may be located in a number of differenthousing units that are fluidly connected (not shown). The canister 122will be discussed in more detail below.

The conduit 110 may be a multi-lumen conduit or tube that provides acontinuous conduit between the reduced pressure interface 114 and thereduced pressure connector 108 positioned on the reduced pressuretreatment unit 106. While the conduit 110 illustrates multiple lumens,it should be appreciated that the reduced pressure treatment system 100may operate using a single lumen tube. The conduit 110 may includeconduits for carrying reduced pressure and removing liquids alone or maybe combined with one or more lumens for sensing pressure and providing avent or a purging capability. The conduit 110 may include a main lumen126 and one or more ancillary lumens 128 and is adapted to maintainfluid isolation between the main lumen 126 and the one or more ancillarylumens 128. Liquids or exudate communicated from the manifold 112through the main lumen 126 are removed from the conduit 110 and retainedwithin the canister 122. The one or more ancillary lumens 128 fluidlycommunicate reduced pressure levels from the tissue site 102 to thesensing unit 130.

In the embodiment illustrated in FIG. 1, the reduced pressure source 124is an electrically-driven vacuum pump. In another implementation, thereduced pressure source 124 may instead be a manually-actuated ormanually-charged pump that does not require electrical power. Thereduced pressure source 124 instead may be any other type of reducedpressure pump, or alternatively a wall suction port such as thoseavailable in hospitals and other medical facilities. The reducedpressure source 124 may be housed within or used in conjunction with thereduced pressure treatment unit 106, which may also contain sensors,processing units, alarm indicators, memory, databases, software, displayunits, and user interfaces 132 that further facilitate the applicationof reduced pressure treatment to the tissue site 102. In one example,pressure-detection sensors (not shown) located in the sensing unit 130may be disposed at or near the reduced pressure source 124. Thepressure-detection sensors may receive pressure data from the reducedpressure interface 114 via the one or more ancillary lumens 128 that arededicated to delivering reduced pressure data to the pressure-detectionsensors. The pressure-detection sensors may communicate with aprocessing unit that monitors and controls the reduced pressure that isdelivered by the reduced pressure source 124.

Referring now primarily to FIGS. 2-7, but still with reference to FIG.1, the canister 122 will be described in more detail. The canister 122is adapted to function in a number of different orientations, and, thus,the canister 122 may be referred to as a multi-orientation canister. Thecanister 122, however, will generally have a primary operatingorientation that will maximize the canister's 122 operational capacityduring reduced pressure tissue treatments. Maximizing the canister's 122operational capacity includes maximizing the life span of any filtersused in the canister 122, reducing or eliminating false canister-fullalarms, and maximizing the canister's 122 volumetric capacity forexudate storage.

The canister 122 is defined by one or more canister walls 134 arrangedto create an enclosure 136. The one or more canister walls 134 maygenerally define the exterior of the canister 122. The canister 122includes an inlet 138, a main chamber 140, a filter chamber 142, and anoutlet 144. In one embodiment, the canister 122 is in its primaryoperating orientation when the inlet 138 is generally positionedsuperior to the main chamber 140 and the filter chamber 142.

The canister 122 may be formed in a number of different ways and from anumber of different materials. As illustrated, with particular clarityin the exploded view of FIGS. 3 and 4, the canister 122 may be formed orassembled by joining a main body 162 with a back face plate 164. In oneembodiment, the main body 162 and the back face plate 164 may be joinedby a tongue-and-groove fitting. In another embodiment, the main body 162and the back face plate 164 may be joined by and adhesive.Pre-assembled, the main body 162 may have a number of recesses, such asrecesses 166 and 168. Likewise, the back face plate 164 may have numberof protrusions, such as protrusions 170 and 172. When assembled, therecesses 166 and 168 may receive the protrusions 170 and 172,respectively. In this embodiment, the joining of the recesses 166, 168with the protrusions 170, 172 define the main chamber 140 and the filterchamber 142. The joining may further define one or more apertures thatprovide fluid communication between the main chamber 140 and the filterchamber 142. It should be appreciated, however, that otherconfigurations may be available. For example, in one embodiment (notshown), the main body 162 may have interior walls that are preformed todefine the perimeters of the main chamber 140 and the filter chamber142. The interior walls may further include preformed apertures thatprovide fluid communication between the main chamber 140 and the filterchamber 142. In this embodiment, the back face plate 164 does notinclude any protrusions that function to substantively join with themain body 162 to form the interior walls that define the main chamber140 and the filter chamber 142.

Referring again primarily to FIGS. 2-7, the inlet 138 is fluidlyconnected with the tissue site 102 and is capable of receiving exudatefrom the tissue site 102. The main chamber 140 is in fluid communicationwith the inlet 138 and is adapted to receive exudate from the inlet 138.In one embodiment, the canister 122 may further include a receivingchamber 146 positioned between the inlet 138 and the main chamber 140.The receiving chamber 146 may be configured so as to inhibit exudatefrom splashing when the exudate is transferred from the inlet 138 to themain chamber 140. In another embodiment, a baffle (not shown) may bepositioned adjacent the inlet 138 to inhibit the splashing of exudate asthe exudate enters the canister 122 through the inlet 138. In yetanother embodiment, a baffle may be positioned adjacent the receivingchamber 146 to provide an additional mechanism to reduced exudatesplash. The receiving chamber 146 includes an aperture 148 for providingfluid communication between the receiving chamber 146 and the mainchamber 140.

The main chamber 140 receives fluids from the inlet 138. A gelling agent(not shown) may be positioned within the main chamber 140. The gellingagent may form a gel upon contact with exudate received from the tissuesite 102. The gel formed from the combination of the gelling agent andthe exudate may help prevent the exudate from splashing around withinthe canister 122 when the canister 122 is moved.

The filter chamber 142 is separated from the main chamber 140 by one ormore filter chamber walls 150 or partitions. The recesses 166, 168 ofthe main body 162 may join with the protrusions 170, 172 of the backface plate 164 to form the one or more filter chamber walls 150. Thefilter chamber walls 150 fluidly separate the main chamber 140 from thefilter chamber 142. In one embodiment, the filter chamber 142 is definedby at least a first filter chamber wall 156 and a second filter chamberwall 158. In this embodiment, the recess 166 may join with theprotrusion 170 to form the first filter chamber wall 156, and the recess168 may join with the protrusion 172 to form the second filter chamberwall 158. The first filter chamber wall 156 may be substantially normalto the second filter chamber wall 158. The one or more filter chamberwalls 150 may intersect with a centroid 160 of the canister 122. The“centroid” referred to herein is the geometric enter of the canister's122 three-dimensional shape based on an average of all points on thecanister 122. The geometric center may coincide with the canister's 122center of mass, however, the geometric center is not required tocoincide with the center of mass. In a specific, non-limitingembodiment, the first filter chamber wall 156 may intersect the centroid160 of the canister 122.

Referring still primarily to FIGS. 2-7, the one or more filter chamberwalls 150 may include or define a first aperture 152 and a secondaperture 154. The first and second apertures 152, 154 may be formed in anumber of different shapes. In specific, non-limiting examples, thefirst and second apertures 152, 154 may be round or square. The firstaperture 152 may be formed through the first filter chamber wall 156 andthe second aperture 154 may be formed through the second filter chamberwall 158. The first aperture 152 is a distance, D, from the secondaperture 154 in three-dimensional space. The first aperture 152 isconfigured to provide a first path of fluid communication between themain chamber 140 and the filter chamber 142. The second aperture 154 isconfigured to provide another path of fluid communication between themain chamber 140 and the filter chamber 142. In one embodiment, thefirst aperture 152 is configured to provide the primary path of fluidcommunication between the main chamber 140 and the filter chamber 142.The first aperture 152 is a first size and the second aperture 154 is asecond size. In one embodiment, the first aperture 152 is larger thanthe second aperture 154. In another embodiment, the first aperture 152is the same size as the second aperture 154. In one embodiment, the sizeof the first and second apertures 152, 154 are configured to preventfluid, upon entering the main chamber 140, from inadvertently splashingor contacting the interior of the filter chamber 142. In anotherembodiment, the size of the first and second apertures 152, 154, areconfigured to prevent gel from entering the filter chamber 142 due tosplashing or sloshing.

The first aperture 152 may be positioned on or adjacent the canister's122 centroid 160. The first aperture 152 may be positioned through thefirst filter chamber wall 156 in a location that is not adjacent to theone or more canister walls 134 that define the exterior of the canister122 to inhibit exudate from entering the first aperture 152 as a resultof exudate sloshing or splashing. In other words, the first aperture 152may be spaced apart from the one or more canister walls 134. The secondaperture 154 may be positioned through the second filter chamber wall158 in a location that maximizes the distance between the first aperture152 and the second aperture 154. In another embodiment, the secondaperture 154 may be positioned through the second filter chamber wall158 as close to the top of the main chamber 140 as possible when thecanister 122 is viewed in its primary operating orientation.

As shown, the outlet 144 is positioned adjacent the filter chamber 142through the one or more canister walls 134. The outlet 144 is adapted toprovide fluid communication between the reduced pressure source 124 andthe filter chamber 142. A filter (not shown) is positioned within thefilter chamber 142. The filter will typically be a hydrophobic filter toprevent exudate and liquids from exiting the canister 122 and reachingthe reduced pressure source 124. In addition to a filter, a liquid-airseparator (not shown) may be placed between the filter and the reducedpressure source 124 for additional protection of the reduced pressuresource 124.

In operation, the reduced pressure source 124 supplies reduced pressureto the tissue site 102 via a fluid communication path linking thereduced pressure source 124 and the tissue site 102. As described above,the manifold 112, the reduced pressure interface 114, the conduit 110,and the canister 122 are all part of the fluid communication pathlinking the reduced pressure source 124 to the tissue site 102. Asreduced pressure is supplied to the tissue site 102, exudate, includingliquids, is removed from the tissue site 102 and deposited within thecanister 122 for storage. The exudate is first deposited in the mainchamber 140 of the canister 122.

The reduced pressure is supplied to the canister 122 via the outlet 144that is in fluid communication with the filter chamber 142. The filterchamber 142 is in fluid communication with the main chamber 140 by meansof the first aperture 152 and the second aperture 154. The secondaperture 154 may be significantly smaller than the first aperture 152such that the first aperture 152 is generally the path of leastresistance for fluid communication between the filter chamber 142 andthe main chamber 140. In the canister's 122 primary operatingorientation, the second aperture 154 may be above or superior inposition to the first aperture 152. In this embodiment, when thecanister 122 first begins to fill with exudate, reduced pressure ismainly supplied from the filter chamber 142 to the main chamber 140 byway of the first aperture 152 because the first aperture 152 generallypresents the path of least resistance. As the main chamber 140 fillswith exudate, the first aperture 152 may become occluded as the fluidlevel in the main chamber 140 reaches the first aperture 152. The firstaperture may be occluded as a result of surface tensions.

If the first aperture 152 becomes occluded or blocked with fluid, thesecond aperture 154 becomes the path of least resistance between thefilter chamber 142 and the main chamber 140. Fluid will continue to fillthe main chamber 140 until the fluid level reaches the second aperture154, occluding or blocking the second aperture 154. In this embodiment,when both the first aperture 152 and the second aperture 154 are blockedby fluid as a result of the main chamber 140 becoming full, the path ofleast resistance between the filter chamber 142 and the main chamber 140is again through the first aperture 152. Sufficient pressure is createdwithin the filter chamber 142 to cause the fluid in the main chamber 140to be pulled into the filter chamber 142 though the first aperture 152.Fluid may continue filling the filter chamber 142 until the fluid levelin the filter chamber 142 fills, blocking the filter and outlet 144. Theconfiguration of the canister 122 increases the useful life span of thefilter by limiting the filter's exposure to exudate before the canister122 is full. Additionally, the configuration of the canister 122increases the canister's useful volumetric capacity for storing exudateby filling the main chamber 140 with fluids before the filter chamber142 is filled with fluids.

In operation, fluids that have entered the filter chamber 142 due tomovement of the canister 122 may be removed or drained from the filterchamber 142. Fluids received from the tissue site 102 are deposited intothe main chamber 140 of the canister 122. The canister 122 may be movedduring operation causing the canister 122 to be rotated into a firstposition, away from the canister's 122 primary operating orientation.The rotation of the canister 122 may cause fluids in the main chamber140 to flow into the filter chamber 142 through either the firstaperture 152 or the second aperture 154. The second aperture 154 beingsuperior in position to the first aperture 152 when the canister 122 ispositioned in its primary operating orientation. If the canister 122 isthen rotated back into a second position, substantially aligned with thecanister's 122 primary operating orientation, the configuration of thecanister 122 in general, and the placement of the apertures 152, 154specifically, allows fluids in the filter chamber 142 to flow back intothe main chamber 140 through the first aperture 152.

In operation, the useful life of the filter positioned in the canister122 may be extended. Fluids from the tissue site 102 are received intothe main chamber 140 of the canister 122. The fluids may react with agelling agent contained within the main chamber 140 to create a gel.Reduced pressure from the reduced pressure source 124 may be applied tothe main chamber 140 via the first aperture 152 until a fluid or gellevel in the main chamber 140 covers or reaches the first aperture 152,causing a temporary blockage of the first aperture 152. In response tothe first aperture 152 becoming temporarily blocked, reduced pressure issupplied to the main chamber 140 via the second aperture 154 until thefluid or gel level in the main chamber 140 covers or reaches the secondaperture 154. The second aperture 154 is superior in position to thefirst aperture 152 when the canister 122 is positioned in its primaryoperating orientation. Additionally, the second aperture 154 issignificantly smaller is size than the first aperture 152 such that thefirst aperture 152 generally provides the path of least resistanceunless only the first aperture 152 is blocked. In response to the fluidor gel level covering the second aperture 154, reduced pressure is againapplied to the main chamber 140 through the first aperture 152 causingthe gel in the main chamber 140 to be pulled into the filter chamber 142until both the main chamber 140 and the filter chamber 142 aresubstantially full of gel.

During operation of another embodiment, the second aperture 154 issubstantially the same size as the first aperture 152. In response to aliquid or gel level covering the first aperture 152, the second aperture154 becomes the path of least resistance. However, in response to theliquid or gel level covering the second aperture 154, reduced pressureis applied to the main chamber 140 through both the first and secondapertures 152, 154 causing the liquid or gel in the main chamber 140 tobe pulled into the filter chamber 142 until both the main chamber 140and the filter chamber 142 are substantially full of liquid or gel.

In one embodiment, the canister 122 is referred to as aliquid-collection canister. The liquid-collection canister includes afirst and second chamber fluidly isolated from one another by one ormore walls. The first chamber may be a main chamber similar to the mainchamber 140 and the second chamber may be a filter chamber similar tothe filter chamber 142. A plurality of apertures may be positioned inthe one or more walls to provide fluid communication between the firstand second chambers. The liquid-collection canister may further includean inlet capable of receiving fluids from a tissue site. The inlet isadapted to provide fluid communication between the tissue site and thefirst chamber. One aperture of the plurality of apertures may bepositioned in a plane perpendicular to another of the plurality ofapertures. The one aperture may have a first diameter larger than asecond diameter of the another of the plurality of apertures. The oneaperture may be positioned below the another aperture in theliquid-collection canister's primary operating orientation. Theliquid-collection canister may further include an outlet for providingfluid communication with the second chamber such that the outlet isadapted to be fluidly connected to a reduced pressure source.

It should be apparent from the foregoing that an invention havingsignificant advantages has been provided. While the invention is shownin only a few of its forms, it is not just limited but is susceptible tovarious changes and modifications without departing from the spiritthereof.

While a number of discrete embodiments have been described, aspects ofeach embodiment may not be specific to only that embodiment and it isspecifically contemplated that features of embodiments may be combinedwith features of other embodiments.

We claim:
 1. A multi-orientational canister for use in a reducedpressure tissue treatment, comprising: an inlet adapted to be fluidlyconnected with a tissue site and capable of receiving fluids from thetissue site; a main chamber in fluid communication with the inlet forreceiving the fluids from the inlet; a filter chamber separated from themain chamber by one or more filter chamber walls; a filter positionedwithin the filter chamber and separated from the main chamber by one ormore of the filter chamber walls; a primary hole having a first diameterpositioned through the one or more filter chamber walls for providing afirst path of fluid communication between the filter chamber and themain chamber; a secondary hole having a second diameter smaller than thefirst diameter positioned through the one or more filter chamber walls;and an outlet providing fluid communication with the filter chamber, theoutlet adapted to be fluidly connected to a reduced pressure source. 2.The multi-orientational canister of claim 1, further comprising thereduced pressure source attached to the filter chamber.
 3. Themulti-orientational canister of claim 1, further comprising a bafflepositioned adjacent the inlet to inhibit splashing of the fluids as thefluids enter the multi-orientational canister through the inlet.
 4. Themulti-orientational canister of claim 1, further comprising a gellingagent positioned within the main chamber for creating a gel upon contactwith the fluids received from the tissue site.
 5. Themulti-orientational canister of claim 1, wherein the multi-orientationalcanister has a primary operating orientation.
 6. The multi-orientationalcanister of claim 5, wherein the primary hole is positioned beneath thesecondary hole in the multi-orientational canister's primary operatingorientation.
 7. The multi-orientational canister of claim 5, wherein theprimary hole is horizontal to a force of gravity when themulti-orientational canister is in the primary operating orientation. 8.The multi-orientational canister of claim 5, wherein the secondary holeis vertical to a force of gravity when the multi-orientational canisteris in the primary operating orientation.
 9. The multi-orientationalcanister of claim 1, wherein the primary hole is positioned on acentroid of the multi-orientational canister.
 10. Themulti-orientational canister of claim 1, wherein the primary hole ispositioned on a center of mass of the multi-orientational canister. 11.A canister for use in a reduced pressure tissue treatment, the canistercomprising: one or more canister walls arranged to create an enclosure;a main chamber positioned within the enclosure configure for collectingexudate received by a tissue site; a filter chamber positioned withinthe enclosure, the filter chamber having a first filter chamber wall anda second filter chamber wall for partitioning the filter chamber fromthe main chamber; a first aperture extending through the first filterchamber wall spaced apart from the one or more canister walls, the firstaperture being positioned on a centroid of the canister; and a secondaperture smaller than the first aperture extending through the secondfilter chamber wall.
 12. The canister of claim 11 further comprising afilter positioned within the filter chamber and partitioned from themain chamber.
 13. The canister of claims 11 further comprising a reducedpressure source attached to the filter chamber.
 14. The canister ofclaim 11 further comprising: a receiving chamber positioned between aninlet of the canister and the main chamber for receiving fluids from thetissue site, the receiving chamber having an aperture for providingfluid communication between the receiving chamber and the main chamber;and a baffle positioned adjacent the receiving chamber aperture toinhibit splashing of fluids as the fluids enter the main chamber. 15.The canister of claim 11 further comprising a gelling agent positionedwithin the main chamber for creating a gel upon contact with the fluidsreceived from the tissue site.
 16. The canister of claim 11, wherein thecanister has a primary operating orientation.
 17. The canister of claim16, wherein the first aperture is positioned beneath the second aperturein the canister's primary operating orientation.
 18. The canister ofclaim 16, wherein the first aperture is horizontal to a force of gravitywhen the canister is in the primary operating orientation.
 19. Thecanister of claim 16, wherein the second aperture is vertical to a forceof gravity when the canister is in the primary operating orientation.20. The canister of claim 16, wherein: the first aperture is positionedbeneath the second aperture in the canister's primary operatingorientation; the first aperture is horizontal to a force of gravity whenthe canister is in the primary operating orientation; and the secondaperture is vertical to the force of gravity when the canister is in theprimary operating orientation.
 21. The canister of claim 11, wherein thefirst filter chamber wall is normal to the second filter chamber wall.22. A canister for use in a reduced pressure tissue treatment, thecanister comprising: a main chamber having an inlet adapted to receivefluid from a tissue site; a filter chamber isolated from the mainchamber by one or more walls, the filter chamber having an outletadapted to be fluidly coupled to a reduced pressure source; a filterpositioned within the filter chamber; and a first aperture and a secondaperture extending through the one or more walls, the first aperture andthe second aperture being sized to prevent the fluid, upon entrance intothe main chamber, from incidentally contacting the filter.
 23. Thecanister of claim 22 further comprising a gelling agent positionedwithin the main chamber for creating a gel upon contact with the fluidreceived from the tissue site.
 24. A reduced pressure delivery systemconfigured for applying a reduced pressure tissue treatment to a tissuesite comprising: a multi-orientational canister comprising: one or morecanister walls arranged to create an enclosure; a main chamberpositioned within the enclosure for receiving exudate from the tissuesite; a filter chamber positioned within the enclosure, the filterchamber having a first filter chamber wall and a second filter chamberwall for partitioning the filter chamber from the main chamber; a firstaperture extending through the first filter chamber wall spaced apartfrom the one or more canister walls, the first aperture being positionedon a centroid of the multi-orientational canister; and a second aperturesmaller than the first aperture extending through the second filterchamber wall; and a reduced pressure source fluidly connected to themulti-orientational canister for applying reduced pressure to the tissuesite; a manifold positioned adjacent the tissue site; and a conduitfluidly connected between the main chamber and the manifold fordelivering fluids from the tissue site to the main chamber.
 25. A methodfor emptying fluids from a filter chamber positioned in a canister usedin reduced pressure tissue treatment, the method comprising: receivingthe fluids into a main chamber of the canister; rotating the canisterinto a first position to cause the fluids in the main chamber to flowinto the filter chamber through either a first aperture or a secondaperture, the first aperture being larger than the second aperture, andthe first aperture being located in a first plane substantiallyperpendicular to a second plane of which the second aperture is located;and rotating the canister into a second position to cause the fluids inthe filter chamber to flow back into the main chamber through the firstaperture.
 26. A method, comprising: receiving fluids into a main chamberof a multi-orientational canister, wherein the fluids react with agelling agent to create a gel; applying reduced pressure to the mainchamber via a first aperture positioned in a partition that separatesthe main chamber from a filter chamber until a fluid or gel level in themain chamber covers the first aperture causing a temporary blockage ofthe first aperture; responsive to the first aperture becomingtemporarily blocked, continuing to apply the reduced pressure to themain chamber via a second aperture positioned in the partition until thefluid or gel level in the main chamber covers the second aperture; andresponsive to the fluid or gel level covering the second aperture,continuing to apply the reduced pressure to the main chamber through thefirst aperture causing the gel in the main chamber to be pulled into thefilter chamber until both the main chamber and the filter chamber aresubstantially full of gel.